This invention is directed to rendering a two-dimensional (xe2x80x9c2Dxe2x80x9d) image from data for a three-dimensional (xe2x80x9c3Dxe2x80x9d) model.
Techniques for rendering a 2D image from a 3D model often focus on achieving a photorealistic (or xe2x80x9ctrue-to-lifexe2x80x9d) effect. A Gouraud-shaded image is an example of the type of image produced using photorealistic rendering. Nonphotorealistic (xe2x80x9cNPRxe2x80x9d) rendering, on the other hand, can produce a 2D image having a sketchy or cartoon-like feel that is similar to hand-drawn images.
In general, in one aspect, the invention features a way of rendering a 2D image from data for a 3D model. According to the invention, a shaded image and an outline image, such as a wireframe or silhouette image, are rendered based on the data. The outline image is rendered with the shaded image to obtain the two-dimensional image.
Among the advantages of the invention may be one or more of the following. Rendering a 2D image from an outline image and a shaded image produces an NPR effect that can be varied by changing one of the images. The rendering process can be implemented on a computer. As a result, multiple NPR 2D images can be produced from a single 3D model merely by repositioning the 3D model and rendering a new 2D image for the model""s new position. This reduces the amount of time and effort expended during the NPR rendering process.